power: domain: Add the VPU Power Domain driver

The Amlogic Meson SoCs embeds a specific Power Domain dedicated to the
Video Processing Unit.
This patch implements support for this power domain in preparation of the
future support for the Video display support in U-Boot.

This driver will depend on changes in the clock driver to handle the setup
of the VPU and VAPB clocks configured from DT using assigned-clocks entries.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
diff --git a/drivers/power/domain/Kconfig b/drivers/power/domain/Kconfig
index 7cfa761..4618847 100644
--- a/drivers/power/domain/Kconfig
+++ b/drivers/power/domain/Kconfig
@@ -16,6 +16,13 @@
 	  Enable support for manipulating BCM6345 power domains via MMIO
 	  mapped registers.
 
+config MESON_GX_VPU_POWER_DOMAIN
+	bool "Enable Amlogic Meson GX VPU power domain driver"
+	depends on ARCH_MESON
+	help
+	  Enable support for manipulating Amlogic Meson GX Video Processing
+	  Unit power domain.
+
 config SANDBOX_POWER_DOMAIN
 	bool "Enable the sandbox power domain test driver"
 	depends on POWER_DOMAIN && SANDBOX